Liquid contact circuit closer



May 3, 1938. e. cARLsoN LIQUID CONTACT CIRCUIT CLOSER Filed March 11,1957 Irwvemtori:

Ge oTgeK/Car 5 oh b 79 M7 MZW y His Attorney Patented May 3, 1938 PATENTOFFICE LIQUID CDNTACT CIRCUIT CLOSER George Carlson, Bridgeport, Conn.,assignor to General Electric Company, a corporation of New YorkApplication March 11,

5 Claims.

In the accompanying drawing, Fig. 1 is a side elevation, partly brokenaway, of a liquid contact circuit closer embodying my invention, thecircuit closer being in thecircuit interrupting position. Figure 2 is asimilar view of the circuit closer, it being in the circuit closingposition, and Fig. 3 is a sectional view taken on line 3-3 of Fig. 1.

Referring to the drawing, I have illustrated my invention applied to aliquid contact circuit closer having a pair of cup-shaped metalterminals I which are separated by a diaphragm comprising abuttingplates 2 and 3 of a refractory material, such as a ceramic. The outeredges of the plates 2 and 3 are provided with shoulders 4 for receivingthe flanges 5 of the terminals. The flanges 5 are sealed by a head 6 ofglass which also seals the junctions between the flanges Sand the plates2 and 3 and the junction between the plates 2 and 3. Within the spaceenclosed by the terminals is a suitable quantity of mercury I whichforms the conducting medium between terminals. In the manufacture of thecircuit closer the space enclosed by the terminals is evacuated andfilled with hydrogen at a pressure of one or more atmospheres whichincreases the current interrupting capacity of the circuit closer. Thediaphragm is provided with a passage formed by openings 8 and 9 in theplates 2 and 3. As shown in Figs. 1 and 2 this passage is submerged inthe mercury when the circuit closer is in the current conductingposition and is raised out of the mercury when the circuit closer is inthe circuit interrupting position. The passage formed by the openings.Band 9 is arranged so that as the circuit closer is moved from thecircuit closing to the circuit interrupting position mercury flowssimultaneously from each end of the passage. In the abutting faces ofthe plates 2 and 3 are recesses forming a depression III in thepassage.formed by the openings 8 and 9. This depression is arranged so that asthe circuit closer is moved to the circuit interrupting position aportion ll of the mercury is retained in the depression. As the circuitcloser is moved to the cir- 1937, Serial No. 130,261

cuit interrupting position the circuit between the terminals is brokenbetween the retained portion II of the mercury and the mercury flowingfrom each of the openings 8 and 9. This provides a double break whichincreases the interrupting capacity of the circuit closer. When thecircuit closer is returned to the position shown in Fig. 2, the mercuryflows into each of the openings 8 and 9 and joins with the pool II tocomplete the circuit between the terminals. Due to the surface tensionof the mercury, there is an are between the particles of mercury duringjoining which is of longer duration than the arc during the separationof the mercury to interrupt the circuit. The are during joining of themercury is also decreased by the presence of the pool lI'. Anotheradvantage resulting from the presence of the pool I I is a decrease inwear due to erosion of "the ceramic in the passage defined by theopenings 8 and 9. This wear is due'to seepage of particles of mercuryinto the interstices of the ceramic and to subsequent arcing of theseparticles which causes the particles of mercury to be forced out of theinterstices with an explosive efiect. Since ceramics are all porous,this type of wear is always present when thediaphragm is a ceramic. Thepresent construction decreases this type of wear since the arcing tendsto be confined to the edges of the pool II.

It will be noted that the shape-of the depression III is such that itholds an increasing amount of mercury as the circuit closer is'moved tothe interrupting position. As the circuit closer is moved to the circuitinterrupting position there is therefore a flow of mercury into thedepression III which aids the separation of the mercury. During movementof the circuit closer to the circuit closing position, there is a flowof mercury from the depression III which aids the joining of .themercury.

In the use of the circuit closer the circuit closer is rotatablysupported for rotation about the axis of its terminals in such a mannerthat the passage defined by the openings 8 and 9 is horizontal. Byrotation of the circuit closer through a small angle the circuit closermay be moved to the circuit closing and circuit interrupting positionsshown in Figs. 1 and 2. As the circuit closer is moved from the circuitclosing position to the circuit interrupting position the circuitbetween the terminals is interrupted between the mercury fiowing fromeach end of the passage defined by openings 8 and 9 and theportion II ofthe mercury retained in the depression III. The circuit interruption,therefore, takes place entirely in the mercury and since it isinterrupted in a plurality of places the circuit interrupting capacityof the switch is increased.

I have shown the diaphragm between the terminals from two abuttingplates of insulating material. It is obvious that a greater number ofplates could be used and that by providing a mercury retainingdepression between each pair of plates the interrupting capacity of thecircuit closer could be further increased.

'What I claim as new and desire to secure by Letters Patent of theUnited States, is:

1. In a liquid contact circuit closer, an envelope having anelectrically conducting liquid therein, a diaphragm separating theliquid into two pools, a terminal contacting the liquid on each side ofthe diaphragm, a passage through the diaphragm for connecting said poolsto complete a circuit between the terminals, said passage being arrangedso that the liquid flows simultaneously from each end thereof as thecircuit closer is moved to a circuit interrupting position in which thepassage is raised above the liquid level in the envelope, and adepression in said passage between its ends for retaining a portion ofthe liquid as the circuit closer is moved to the circuit interruptingposition whereby the circuit is broken from each side of the retainedliquid, said depression being constructed so that the liquid retainedtherein is raised above the liquid level in the envelope as the passageis raised above the liquid level.

2. In a liquid contact circuit closer, an -envelope for an electricallyconducting liquid comprising a pair of opposed cup-shaped metalterminals, a diaphragm between the adjacent edges of said terminals,said diaphragm comprising a plurality of abutting plates, a bead ofsealing material joining said terminals and sealing the junction betweensaid plates, openings in said plates providing a. passage through thediaphragm for completing a circuit between the terminals, said passagebeing arranged so that the liquid flows simultaneously from each endthereof as the circuit closer is moved to a circuit interruptingposition in which the passage is raised above the liquid level in theenvelope, and a recess in the abutting face of one of said platesproviding a depression in said passage between its ends for retaining aportion of the liquid as the circuit closer is moved to the circuitinterrupting position .whereby the circuit is broken from each side oftheretained liquid, said depres= sion being constructed so that theliquid retained therein is raised above the liquid level in the envelopeas the passage is raised above the liquid level.

3. In' a liquid contact circuit closer, an envelope having anelectrically conducting liquid therein, a diaphragm separating theliquid into two pools, said diaphragm comprising a plurality oi.abutting plates, a terminal contacting the liquid on each side of thediaphragm, openings in said plates providing a passage through thediaphragm for connecting said pools to complete a circuit between theterminals, said passage being arranged so that the liquid flowssimultaneously from each end thereof as the circuit closer is moved to acircuit interrupting position in which the passage is raised above theliquid level in the envelope, and a recess in the abutting face of 'oneof said plates providing a depression in said passage between its endsfor retaining a portion of the liquid as the circuit closer is moved tothe circuit interrupting position whereby the circuit is broken fromeach side of the retained liquid, said depression being constructed sothat the liquid retained therein is raised above the liquid level in.the envelope as the passage is raised above the liquid level.

having an electrically conducting liquid therein,

a diaphragm separating the liquid into two pools,

a terminal contacting the liquid on each side of the diaphragm, apassage through the diaphragm for connecting said tools to complete acircuit between the terminals, said passage being arranged so that theliquid flows simultaneously from each end thereof as the circuit closeris moved to a circuit interrupting. position, and a depression in saidpassage between its ends for retaining a portion of the liquid as thecircuit closer is moved to the circuit interrupting position whereby thecircuit is broken from each side of the retained liquid, said depressionbeing shaped so that the volume of liquid held therein increases as thecircuit closer is moved from the circuit closing to the circuitinterrupting position.

5. Ina liquid contact circuit closer, an envelope having a quantity ofmercury therein, a barrier separating the mercury into two pools, aterminal contacting the mercury on each side of the barrier, a passageover the barrier for connecting said pools to complete a circuit betweenthe terminals, said passage being arranged so that the mercury flowssimultaneously from each end thereof as the circuit closer is moved to acircuit interrupting position in which the passage is raised above theliquid level in the envelope, said passage having a ceramic surface overwhich the mercury flows, and a depression in said passage between itsends for retaining a portion of the mercury as the circuit closer ismoved to the circuit interrupting position whereby the circuit is brokenfrom each side of the retained mercury, said depression beingconstructed so that the liquid retained therein is raised above theliquid level in the envelope as the passage is raised above the liquidlevel.

GEORGE CARLSON.

e RT FIcA'TE 0F CORRECTION. I

Patent No. 2,116,585. may 5; 959

- GEORGE cABLsoN.

It is hereby certified that error appears gin theprint ed specificationof the above numbered patent requiringeor renation as follows: Page 2,second column, line 26, claim 1 for the word "tools" read pools; andthatthe said Letters Patent. should be read with thie correction thereinthat the same may conform to the record of, the case in Nae PatentOffice.

Signed. and sealed thie'lhth day of J1me, A., D. 19 8'.

Henry Van Arsda-le (Seal? :Acting cennnissioner of Patents.

